Sensitivity of the ATLAS Experiment to Extra Dimensions

In the late nineties several authors suggested that the extra dimensions predicted by string theory might lead to observable effects at high energy colliders. The ATLAS experiment which will start taking data at the LHC in 2007 will be an excellent place to search for such effects. A large set of models within the ADD or the Randall Sundrum geometries has been studied in ATLAS. These models predict a variety of signatures: jets and missing energy from direct graviton production, high mass tails in dilepton and diphoton production due to virtual graviton exchange, production of Kaluza-Klein excitations of standard model particles, etc. The sensitivity of ATLAS to these signatures will be presented

Rational-Emotive Therapy: A Cognitive-Behavioral Approach to Working with Hearing Impaired Clients

This paper serves to present to deafness rehabilitation specialists the basic assumptions and process of Rational-Emotive Therapy. As a forerunner in the field of cognitive-behavioral therapy, RET provides a framework and specific interventions to meet a wide variety of client needs. A discussion of suggested techniques designed specifically for a portion of the deaf population is included. The flexibility of the RET approach in offering the options of both elegant and inelegant resolution of emotional disturbance enhances the usefulness of this theory with the diverse population of deaf clients

Modular Quantum Memories Using Passive Linear Optics and Coherent Feedback

In this paper, we show that quantum memory for qudit states encoded in a single photon pulsed optical field has a conceptually simple modular realization using only passive linear optics and coherent feedback. We exploit the idea that two decaying optical cavities can be coupled in a coherent feedback configuration to create an internal mode of the coupled system which is isolated and decoherence-free for the purpose of qubit storage. The qubit memory can then be switched between writing/read-out mode and storage mode simply by varying the routing of certain freely propagating optical fields in the network. It is then shown that the qubit memories can be interconnected with one another to form a qudit quantum memory. We explain each of the phase of writing, storage, and read-out for this modular quantum memory scheme. The results point a way towards modular architectures for complex compound quantum memories

Probing Solar Convection

In the solar convection zone acoustic waves are scattered by turbulent sound speed fluctuations. In this paper the scattering of waves by convective cells is treated using Rytov's technique. Particular care is taken to include diffraction effects which are important especially for high-degree modes that are confined to the surface layers of the Sun. The scattering leads to damping of the waves and causes a phase shift. Damping manifests itself in the width of the spectral peak of p-mode eigenfrequencies. The contribution of scattering to the line widths is estimated and the sensitivity of the results on the assumed spectrum of the turbulence is studied. Finally the theoretical predictions are compared with recently measured line widths of high-degree modes.Comment: 26 pages, 7 figures, accepted by MNRA

The many faces of disability in evidence for policy and practice: embracing complexity

Background: This special issue examines the relationship between disability, evidence, and policy. Key points: Several themes cut across the included papers. Despite the development of models of disability that recognise its socially constructed nature, dis/ableism impedes the involvement of people with disability in evidence production and use. The resultant incomplete representations of disability are biased towards its deproblematisation. Existing data often homogenise the heterogeneous. Functioning and impairment categories are used for surveys, research recruitment and policy enactments, that exclude many. Existing data may crudely evidence some systematic inequalities, but the successful and appropriate development and enactment of disability policies requires more contextual data. Categories and labels drawn from a deficit model affect social constructions of identity, and have been used socially and politically to justify the disenfranchisement of people with disability. Well rehearsed within welfare systems, this results in disempowered and devalued objects of policy, and, as described in one Brazilian paper, the systematic breakup of indigenous families. Several studies show the dangers of policy developed without evidence and impact assessments from and with the intended beneficiaries. Conclusions and implications: There is a need to mitigate barriers to inclusive participation, to enable people with disability to collaborate as equals with other policy actors. The combined application of different policy models and ontologies, currently in tension, might better harness their respective strengths and encourage greater transparency and deliberation regarding the flaws inherent in each. Learning should be shared across minority groups

Longevity and mortality of cats attending primary care veterinary practices in England

Enhanced knowledge on longevity and mortality in cats should support improved breeding, husbandry, clinical care and disease prevention strategies. The VetCompass research database of primary care veterinary practice data offers an extensive resource of clinical health information on companion animals in the UK. This study aimed to characterise longevity and mortality in cats, and to identify important demographic risk factors for compromised longevity. Crossbred cats were hypothesised to live longer than purebred cats. Descriptive statistics were used to characterise the deceased cats. Multivariable linear regression methods investigated risk factor association with longevity in cats that died at or after 5 years of age. From 118,016 cats attending 90 practices in England, 4009 cats with confirmed deaths were randomly selected for detailed study. Demographic characterisation showed that 3660 (91.7%) were crossbred, 2009 (50.7%) were female and 2599 (64.8%) were neutered. The most frequently attributed causes of mortality in cats of all ages were trauma (12.2%), renal disorder (12.1%), non-specific illness (11.2%), neoplasia (10.8%) and mass lesion disorders (10.2%). Overall, the median longevity was 14.0 years (interquartile range [IQR] 9.0–17.0; range 0.0–26.7). Crossbred cats had a higher median longevity than purebred cats (median [IQR] 14.0 years [9.1–17.0] vs 12.5 years [6.1–16.4]; P \u3c0.001), but individual purebred cat breeds varied substantially in longevity. In cats dying at or after 5 years (n = 3360), being crossbred, having a lower bodyweight, and being neutered and non-insured were associated with increased longevity. This study described longevity in cats and identified important causes of mortality and breed-related associations with compromised longevity

Green's functions for far-side seismic images: a polar expansion approach

We have computed seismic images of magnetic activity on the far surface of the Sun by using a seismic-holography technique. As in previous works, the method is based on the comparison of waves going in and out of a particular point in the Sun but we have computed here the Green's functions from a spherical polar expansion of the adiabatic wave equations in the Cowling approximation instead of using the ray-path approximation previously used in the far-side holography. A comparison between the results obtained using the ray theory and the spherical polar expansion is shown. We use the gravito-acoustic wave equation in the local plane-parallel limit in both cases and for the latter we take the asymptotic approximation for the radial dependencies of the Green's function. As a result, improved images of the far-side can be obtained from the polar-expansion approximation, especially when combining the Green's functions corresponding to two and three skips. We also show that the phase corrections in the Green's functions due to the incorrect modeling of the uppermost layers of the Sun can be estimated from the eigenfrequencies of the normal modes of oscillation.Comment: 8 pages, 5 figures, Astrophysical Journal, accepted (2010

Medipix3 Demonstration and understanding of near ideal detector performance for 60 & 80 keV electrons

In our article we report first quantitative measurements of imaging performance for the current generation of hybrid pixel detector, Medipix3, as direct electron detector. Utilising beam energies of 60 & 80 keV, measurements of modulation transfer function (MTF) and detective quantum efficiency (DQE) have revealed that, in single pixel mode (SPM), energy threshold values can be chosen to maximize either the MTF or DQE, obtaining values near to, or even exceeding, those for an ideal detector. We have demonstrated that the Medipix3 charge summing mode (CSM) can deliver simultaneous, near ideal values of both MTF and DQE. To understand direct detection performance further we have characterized the detector response to single electron events, building an empirical model which can predict detector MTF and DQE performance based on energy threshold. Exemplifying our findings we demonstrate the Medipix3 imaging performance, recording a fully exposed electron diffraction pattern at 24-bit depth and images in SPM and CSM modes. Taken together our findings highlight that for transmission electron microscopy performed at low energies (energies <100 keV) thick hybrid pixel detectors provide an advantageous and alternative architecture for direct electron imagin